Such apparatuses are known in their conventional form of embodiment as a biplane X-ray system. Each pair of X-ray source and X-ray detector can record X-ray images. The pairs are arranged such that an image of the same object is able to be recorded by both pairs, especially simultaneously. The object is typically located on a patient table which is located in the beam path from the X-ray source to the X-ray detector for both pairs, or this state is at least able to be established, be it by a movement of the patient table or be it by a movement of the X-ray source and X-ray detector.
Under normal circumstances there are means to move the X-ray source and the X-ray detector, i.e. to bring the same into specific positions. Typically a pair comprising X-ray source and X-ray detector are coupled and moved together, however the present invention is also able to be used if the X-ray source and the X-ray detector of a pair are able to be moved independently of one another.
In a biplane X-ray system from the applicant's own company Siemens AG for example, an X-ray C-arm is suspended from the ceiling of a room, a second arm is coupled to a floor mount.
The advantage of simply providing two pairs of X-ray source and X-ray detector is that of enabling the presentation to be switched very rapidly: A doctor carrying out the treatment can X-ray a patient with the aid of the first pair of X-ray source and X-ray detector from a prespecified perspective and can then switch the perspective very rapidly by using the second pair of X-ray source and X-ray detector. It is known from DE 102 41 184 A1 that a volume dataset of an object is able to be calculated from the X-ray images (2D projections) obtained by the two pairs of X-ray source and X-ray detector, especially synchronously.
In a hospital environment it is a matter of utilizing available devices in the optimum possible manner. It is therefore advantageous for them to be versatile in their uses.
Said biplane X-ray systems are used in particular to support imaging in minimally-invasive interventions and surgical procedures on patients. In such procedures it is of importance for the doctor carrying out the treatment to obtain images, of soft tissue for example; these can be useful for procedures on the heart and liver. A flat-panel X-ray detector with a good local resolution is thus required. For example such a flat-panel detector has detector elements of the size of around 100 μm. Such a detector can be constructed from amorphous Silicon or with the aid of CMOS technology. Future developments are designed to manufacture such flat-panel detectors from Cadmium-Telluride (CdTe) or Cadmium-Zinc-Telluride, or on the basis of organic photodiodes. Such flat-panel detectors are especially usually used in their amorphous silicon versions in X-ray angiography systems.
For recording images of the heart with the aid of computed tomography quite different types of detector are used, namely such as can record images with high frequencies, in order to record the heart multiple times during a heart cycle. These types of computed tomography detectors typically consist of UFC (ultra-fast-ceramic), or they are based on Yttrium-Gadolinium-Oxide, in future also on Cadmium-Telluride (CDTE) or on Cadmium-Zinc-Telluride. Such detectors optimized for a high temporal resolution have the disadvantage of their detector elements having the size of around 400 μm, so that they only offer a limited local resolution.
In the prior art the doctor performing the treatment thus has to decide before an intervention which type of imaging is more important for him, either that with high spatial resolution or that with a faster temporal sequence of image recording; he must then treat his patient at a specific device. In addition the two types of device are not always available in a hospital environment.